Opening cylinder for an open-end spinning device

ABSTRACT

The invention relates to an opening cylinder ( 2 ) of an open-end spinning device as well as a fiber sliver opening apparatus with such an opening cylinder. In at least one lateral area ( 6 ) of the opening cylinder ( 2 ) a sealing surface for an air gap seal ( 12 ) is formed. According to the invention the opening cylinder ( 2 ) has an air passage ( 14 ) in at least the one lateral area ( 6 ), the output side of the air passage lying within the sealing surface or adjoining the sealing surface directly and the input side of which being at a shorter distance from the rotational axis of the opening cylinder ( 3 ) than the output side. During the operation of the fiber sliver opening apparatus, air is conveyed through the passages ( 14 ) to the air gap ( 12 ) of the air gap seal arrangement or conveyed past it, so that the entry of air and pollutants into the air gap ( 12 ) is counteracted.

[0001] The invention relates to an opening cylinder of an open-end spinning device provided in at least one lateral area with a sealing surface for an air gap seal.

[0002] In a known fiber sliver opening apparatus of an open-end spinning device (DE 196 51 417 A1) a rotatably supported opening cylinder is located in a housing of the fiber sliver opening apparatus. The opening cylinder consists of a basic body with the drive shaft, an exchangeable card clothing and an opening cylinder covering element whose front closes off the housing of the fiber sliver opening apparatus on one side. A multi-surface contour is formed on the outside of the opening cylinder cover and is located across from a corresponding, multi-surface contour of the housing, with a small air gap left between the multi-surface contours. The placement of the contours in close proximity is designated as a stepped sealing arrangement or labyrinth seal and allows for a rotational movement of the opening cylinder cover relative to the housing while at the same time increasing the air resistance to an air current from the outside of the fiber sliver opening apparatus to the inside, where a negative pressure is applied by the fiber removal suction and must be maintained. Limits are set to reduction of the air gap between the housing and the opening cylinder cover by the manufacturing and assembly tolerances as well as by oscillations occurring during the operation of the fiber sliver opening apparatus.

[0003] In another known fiber sliver opening apparatus (U.S. Pat. No. 3,800,520) two laterally extending segments, each with a sealing surface for an air gap seal, are formed on the opening cylinder rotatably supported in the opening cylinder housing. Each of the exit sides of the air gap seal is connected to atmospheric pressure, so that the pressure drops between the atmospheric pressure and the slight negative pressure within a cavity between the opening cylinder and the opening cylinder housing and external air penetrates into the cavity. Due to this air flow the costs for the production of the negative pressure required in the cavity to suck the fibers detached by the opening cylinder.

[0004] It is therefore the object of the invention to provide an opening cylinder for an open-end spinning device and a fiber sliver opening apparatus with such an opening cylinder where the air current is reduced by an air gap between the opening cylinder and a housing of the fiber sliver opening apparatus containing the opening cylinder, and where the depositing of dirt in the gap is reduced.

[0005] This object is attained through the charact eristics of claims 1, 12 or 14.

[0006] In a fiber sliver opening apparatus according to the characteristics of the introductory clauses of claim 1, at least one lateral area of an opening cylinder is provided with a passage and/or channel for air, whereby its input side is closer to the rotation axis of the opening cylinder than the output side. During the operation of the fiber sliver opening apparatus the opening cylinder has a rotational speed of approximately 6000 to 9000 RPM. Due to the high rotational speed and the outward orientation of the passage or channel, the air in the passage or channel is conveyed by the centrifugal force in the direction of the output side. This means that because the input side is at a closer radial distance from the rotational axis than the output side, an air flow is therefore induced through the passage or channel when the opening cylinder rotates.

[0007] As compared with the air passage, the air passage is at least partially not enclosed on all sides in flow direction, but allows for a lateral escape or entry of air into the channel. Thereby the efficiency of air movement in the direction of the air gap is lower than with a passage, but also results in an air flow in the direction of the air gap. To that extent, the effect of the passage mentioned below, also applies if an air channel is used, and should include the latter as a replacement.

[0008] The outlet side of the passage is open towards an air gap between the opening cylinder and the housing of the fiber sliver opening apparatus or adjoins the air gap directly. As a result the air flowing through the passage can flow either into the air gap or flow past it in immediate proximity. In this case the input side of the passage is advantageously open to the outside atmosphere, so that the outside air is guided through the passage.

[0009] The air coming from the passage causes a dynamic pressure in the air gap when the output side is in proximity of the air gap, or a suction action relative to the air gap if the output side adjoins the air gap. By providing several passages on the opening cylinder part, air movement comparable to a radial air blowing system can be achieved.

[0010] The dynamic air pressure in the air gap prevents air from entering from the outside through the air gap into the interior of the fiber sliver opening apparatus. Thereby the air flow into the interior of the fiber sliver opening apparatus is reduced and energy costs of maintaining the vacuum are lowered. At the same time the air flowing through the passage blows pollutants out of the air gap, so that a deposit of pollutants and finally the friction of the contour surfaces against each other is prevented.

[0011] If however the air current flows out of the passages in immediate proximity of the air gap, the strong air flow coming out of the passages produces a negative pressure towards the air gap (Venturi effect) acting against the entry of outside air into the air gap. Pollutants from the outside are here also blown out of the vicinity of the air gap.

[0012] In an advantageous embodiment the sealing surface (at least one being present) is made in form of a contour surface and interacts with a contour surface of the housing across from it when the opening cylinder has been installed in the opening cylinder housing, so that an air gap sealing arrangement or labyrinth seal is produced. The surfaces can be e.g. stepped, in form of saw teeth, or in form of meanders.

[0013] If passages are provided on the opening cylinder at a first sealing surface as well as at a second sealing surface for an air gap seal, the airflow into the interior of the fiber sliver opening apparatus is reduced on both sides of the opening cylinder and the deposit of dust is avoided.

[0014] If the sealing surface and (at least one) air channel are formed in a lateral part that is separated from the opening cylinder, the manufacture of the sealing surface and of the air channels or channel is simplified. In addition, the lateral part can be detached for maintenance or cleaning of the opening cylinder, or the opening cylinder can be removed from the lateral part.

[0015] In an especially advantageous embodiment a circumferential border or an outer collar is made, the outside circumference of which is part of the sealing surface of the opening cylinder and on the inside circumference and/or lateral surface of which the input sides of the passages are formed. If the input sides are at the inside circumference, making the passages is especially easy by drilling, in that the collar is perforated from the outside at one or several locations.

[0016] If the passages in the opening cylinder part are radial, approximately radial or helicoidal relative to the axis of rotation of the opening cylinder, the centrifugal force acting on the air in the passage is utilized especially well, and strong air flow towards the air gap can be achieved.

[0017] If the passages emerge at an angle from the axis of rotation of the opening cylinder in direction of its face, the airflow from the passages is aligned in an especially efficient manner, flowing past the air gap, so that the suction action of the passing air stream is especially strong and the Venturi effect thereby especially effective. This is further assisted in another embodiment in that the cross-section of the passages decreases towards the outside so that the output speed of the air is increased.

[0018] By increasing the number of passages to such an extent that they are adjoining each other with only a ridge separating them from each other, the quantity of airflow in the direction of the air gap is maximized. In this case it is possible to rout the passages from an axial direction into the lateral opening cylinder area and, following routing, to lay an annular disk over the routed passages so as to then constitute a face of the opening cylinder.

[0019] Examples of embodiments of the invention are explained through drawings.

[0020]FIG. 1 Shows a fiber sliver opening apparatus with a first example of an embodiment of air passages in the opening cylinder cover,

[0021]FIG. 2 shows a second example of an embodiment for air passages in the opening cylinder cover,

[0022]FIG. 3 shows a third example of an embodiment for air passages in the opening cylinder cover,

[0023]FIG. 4 shows a fourth example of an embodiment for air passages in the opening cylinder cover,

[0024]FIG. 5 shows a schematic top view of a lateral part of the rear of an opening cylinder housing,

[0025]FIG. 6 shows a first example of an embodiment of a rear air gap seal,

[0026]FIG. 7 shows a second example of an embodiment of a rear air gap seal and

[0027]FIG. 8 shows a third example of an embodiment of a rear air gap seal.

[0028]FIG. 1 shows a cross-sectional view of a fiber sliver opening apparatus whereby a rotatably supported opening cylinder 2 is installed in an opening cylinder housing 1. The opening cylinder 2 is composed of a basic body 4; an opening card clothing 5 and an opening cylinder cover 6. The drive shaft 3 is mounted supported by two ball bearings 8 in the housing 1 of the fiber sliver opening apparatus. A drive wharve 7 over which a drive belt driving the opening cylinder 2 runs is attached at one end of the drive shaft 3 which protrudes from the opening cylinder housing 1. The basic body 4 is fixed at the other end of the drive shaft 3 within the opening cylinder housing 1 by means of a counter-bearing flange for the card clothing 5. The exchangeable card clothing 5 is clamped between the basic body 4 and the opening cylinder cover 6. The opening cylinder cover 6 is attached to the drive shaft 3 by means of a screw (not shown) that is introduced into an opening 9 of the opening cylinder cover 6 and is screwed into inside threads 10 in the drive shaft 3.

[0029] A fiber sliver is conveyed to the opening cylinder 2 through a feed opening 11 in the opening cylinder housing by a feed apparatus not shown here. The fibers of the fiber sliver are detached from the fiber sliver by the opening cylinder 2, are sucked through an outlet opening (not shown) in the opening cylinder housing 1 from the latter and are conveyed in the direction of the spinning rotor of a rotor spinning device.

[0030] An additional opening towards the interior of the opening cylinder housing 1 is the air gap 12 between the opening cylinder cover 6 and the adjoining surfaces of the opening cylinder housing 1 required for the rotation of the opening cylinder 2. The width of the air gap 12 is kept so small in this case that a rotation of the opening cylinder cover 6 relative to the opening cylinder housing 1 is possible without contact despite existing manufacturing tolerance and possibly occurring oscillations of the opening cylinder 2.

[0031] In order to further reduce the air flow through the air gap 12 from the outside of the opening cylinder housing 1 into its interior, four air passages 14, each at the same angular distance from the other are provided on the circumference of the opening cylinder cover 6 at an outer collar 13 or at a border of the opening cylinder cover 6. In the first embodiment of the air passages 14 represented in FIG. 1, these are perpendicular to the rotational axis of the opening cylinder 2, going in radial direction from the opening 9 to the air gap 12.

[0032] Due to the high rotational speed of the opening cylinder 2, in the range of 6000 RPM, the air passages 14 act as radial air blowers and accelerate the air in the air passages 14 under the effect of centrifugal force in the direction of the air gap 12. There the air emerging from the air passages 14 create a dynamic pressure which counteracts the entry of air from the outside of the opening cylinder housing 1.

[0033]FIG. 2 shows part of a cross-section of part of the opening cylinder housing 1 and of the opening cylinder cover 6 in the outer collar 13 of which an air passage 14 a according to a second embodiment is formed. The air passage 14 a forms an angle of approximately 60° with the rotational axis of the opening cylinder 2. As a result the air current flows at an angle of 60° from the air passage 14 a into the air gap 12 and causes an air flow to go from the air passage 14 a to the output side of the air gap 12 at the front of the fiber sliver opening apparatus. Due to the air flow in the air gap 12, a negative pressure is created at the output side of the air passage 14 a in the area of the air gap 12 that follws the output side of the air passage 14 a in the direction of the interior of the opening cylinder housing 1. This negative pressure prevents on the one hand the entry of outside air into the opening cylinder housing 1 and on the other hand creates additional negative pressure in the air gap 12 which diverts the air from the air gap 12 to the outside.

[0034]FIG. 3 shows a third embodiment of an air passage 14 b the output side of which directly adjoins the outer end of the air gap 12. The air flows from the air passage 14 b at high speed past the air gap 12 and thereby generates a negative pressure that sucks the air from the air gap 12 as mentioned above, and creates a negative pressure in it.

[0035]FIG. 4 shows a section of a cross-section perpendicular to the rotational axis of the opening cylinder cover 6, trough the outer collar 13. Air passages 14 c are made in the collar 13 in a fourth embodiment. The air passages 14 c extend from the inside of the outer collar approximately in helicoidal fashion to the rotational axis of the opening cylinder 2 and the cross-section of the air passages 14 c decreases in size from the inside to the outside of the outer collar 13. As a result the acceleration of the air in the air passage 14 c is heightened on the one hand as in a radial air blower, and on the other hand the speed of the air flow through the air passage 14 c to the output side increases due to the tapering cross-section. Thus the conveyed quantity of air and the suction action caused by the air speed are further increased.

[0036] The special design of the embodiments described above can be combined in any way desired. Thus for example, the air passage can be helicoidal with respect to the rotational axis, can be provided with a cross-section decreasing in size towards the output side and be at an angle of less than 90° relative to the rotational axis.

[0037]FIG. 5 schematically shows a top view of the rear lateral wall 20 of an opening cylinder housing 1. The lateral wall 20 is perforated by the opening 21 so that the outside atmosphere can go from the outside of the opening cylinder housing 1 to the rear lateral area of an opening cylinder 23. A shaft 24 of the opening cylinder 23 goes through a bore 22 in the lateral wall 20. The openings 21 correspond to the area marked A in FIG. 1 of the rear of the opening cylinder housing 1 of the first embodiment example.

[0038]FIG. 6 shows a section of the 23 and of the opening cylinder housing 25 in a cross-section. An inside space 26 between the opening cylinder 23 and the housing 25 is connected via a first embodiment of a rear air gap seal 27 to the outer atmosphere 28. At the rear lateral surface of the opening cylinder 23 a projecting, circumferential border 29 is formed. The border is perforated at several locations in radial direction so that air passages 30 are constituted in the border.

[0039] During the rotation of the opening cylinder 23 the air is conveyed in the air passages to the outer circumference of the border 20 so that an air flow represented by arrows in FIG. 6 is guided past the rear air gap seal 27.

[0040]FIG. 7 shows a second embodiment of a rear air gap seal 40, whereby the opening cylinder and the opening cylinder housing 25 are designed as the elements shown in a partial cross-section in FIG. 6. At the rear lateral area of the opening cylinder 23 a stepped border 41 is formed circumferentially. Bores 42 extending away from the rotational axis of the opening cylinder 23 and are at an angle to the rotational axis are provided in the border 41. The output sides of the bores 42 are at the lateral surface of the border 41 and blow an air stream pst the air gap 40 in its immediate proximity as the opening cylinder rotates.

[0041]FIG. 8 shows a third embodiment of the rear air gap seal 50. The elements are essentially as the elements shown in FIG. 6 and are designated by the same reference numbers. The opening cylinder 23 and the opening cylinder housing 25 differ from the elements shown in FIG. 6 by the two-part design of the opening cylinder housing 25 and of the air gap arrangement 50. The housing is composed of a rear bearing element 51 for the support of the shaft 24 and a forward cover 52. A border 53 in which air passages 54 extending in radial direction are provided is formed at the rear lateral area of the opening cylinder 23. As the opening cylinder 23 rotates, air is blown through the air passages 54 into the air gap 50.

[0042] A first segment 55 of the air gap 50 extends from the interior space 26 in radial direction to the outside. The rotation of the lateral surface of the border 53 which adjoins the first segment 55 accelerates the air in this air gap segment 55 radially to the outside, so that the sealing action, in addition to high air resistance, is further assisted by the centrifugal force because of the narrow gap. 

1. Opening cylinder of an open-end spinning device with at least one sealing surface in a lateral area (6) for an air gap seal (12, 27, 40, 50), characterized in that at least in the one lateral area (6) of the opening cylinder (2, 23) at least one air passage (14, 14 a, 14 b, 14 c, 30, 42, 54) or air channel is formed, the output side of which is located in the sealing surface or next to the sealing surface and the input side is at a shorter distance from the rotational axis of the opening cylinder (2, 23) than the output side.
 2. Opening cylinder as in claim 1, characterized in that the sealing surface is in form of a contour surface.
 3. Opening cylinder as in claim 1 or 2, characterized in that a first lateral area (6) of the opening cylinder (2, 23) is provided with a first sealing surface, and a second lateral area of the opening cylinder (2, 23) is provided with a second sealing surface, whereby at least one air passage or air channel adjoins the first as well as the second sealing surface and/or lets out into it.
 4. Opening cylinder as in claim 1, 2 or 3, characterized in that the lateral area (6) is made in form of a separate lateral opening cylinder element comprising the sealing surface.
 5. Opening cylinder as in one of the preceding claims, characterized in that a circumferential collar (13, 29, 41, 53) is formed at the face of the lateral area (6), its outer circumference being at least a part of the sealing surface of the opening cylinder (2, 23) and on whose inner circumference and/or lateral surface the inlet side of the air passage (14, 14 a, 14 b, 14 c, 30, 42, 54) of which at least one is provided is formed.
 6. Opening cylinder as in one of the preceding claims, characterized in that the passages (14, 14 a, 14 b, 30, 42, 54) or air channels extend radially or approximately radially.
 7. Opening cylinder as in one of the preceding claims, characterized in that the passages (14 c) are designed so as to extend helicoidally relative to the rotational axis of the opening cylinder (2).
 8. Opening cylinder as in one of the preceding claims, characterized in that the passages (14 a, 14 b, 42) extend at least near the outlet side at an angle of less than 90° to the rotational axis of the opening cylinder (2, 23).
 9. Opening cylinder as in one of the preceding claims, characterized in that the cross-section of the passages (14 c) decrease in size towards their output side.
 10. Opening cylinder as in one of the preceding claims, characterized in that the passages adjoining each other are separated from each other by ridges.
 11. Opening cylinder as in one of the preceding claims, characterized by a basic body (4) attached on a shaft (3) and an opening cylinder covering element (6) on which a card clothing (5) is provided or with which an exchangeable card clothing (5) can be attached to the basic body (4) in a detachable manner, whereby the opening cylinder covering element (6) is provided with the sealing surface.
 12. Opening cylinder covering element for an opening cylinder, on which an exchangeable card clothing can be attached so as to be detachable from the basic body (4) of the opening cylinder (2) and provided with a sealing surface for an air gap seal (12), characterized in that at least one air passage (14, 14 a, 14 b, 14 c,) or air channel is formed in a lateral area of the opening cylinder covering element (6), the output side of which lies in the sealing surface or directly adjoins the sealing surface, and the input side of which is at a shorter radial distance from the rotational axis of the opening cylinder (2, 23) than the output side.
 13. Opening cylinder covering element as in claim 12, characterized in that that the air passage (14, 14 a, 14 b, 14 c) or air channel is designed according to one of the claims 7 to
 10. 14. Fiber sliver opening apparatus of an open-end spinning device with a housing (1, 25) and an opening cylinder (2, 23) rotatably installed in the housing as in one of the claims 1 to 11, whereby the sealing surface (at least one being provided) of the opening cylinder (2, 23) is across from a corresponding sealing surface of the housing (1, 25) with a small air gap (12, 27, 40, 50) between them. 